74 



A BIOLOGY OF CRUSTACEA 



Fig. 33. C, Metanauplius of Limnadia lenticularis (Con- 

 chostraca, ventral view. Note the enormous labrum. 



The copepodid moults five times before attaining maturity. The 

 parasitic copepods often have highly modified life histories — some 

 of these are dealt with in chapter 8. 



In the cirripedes the nauplius is followed by the cypris (fig. 35). 

 This larva has the carapace extending down the sides of the body 

 so that the creature looks superficially like an ostracod. When it is 

 examined carefully it is seen to be very different from an ostracod, 

 particularly in the number of limbs. It is the cypris which attaches 

 to a solid object and changes into the adult. 



Fig. 34 A, Metanauplius of Artemia salina (Anostraca), ventral 

 view. Note the elongated body and the absence of limbs on the 

 thorax. B, Young Triops cancrtformis, the nauplius stage has 

 been passed and the carapace developed to look like the adult, 

 but the creature still swims with the large antennae, even though 

 the thoracic limbs are developing. Compare with figs. 5 and 19. 



